Retrofit Annotation

InterceptedInterceptor.kt

class InterceptedInterceptor : Interceptor {
    override fun intercept(chain: Interceptor.Chain): Response =
            try {
                val invocation = chain.request().tag<Invocation>()
                val annotation = invocation?.method()?.annotation<Intercepted>()
                (annotation?.value?.java?.constructors?.first()
                        ?.newInstance(invocation.arguments()) as Interceptor?)?.intercept(chain)
            } catch (e: Throwable) { null } ?: chain.proceed(chain.request())
}

class InterceptedRequestInterceptor(
        private val interceptors: Map<KClass<out RequestInterceptor>, RequestInterceptor> = emptyMap(),
) : RequestInterceptor {
    val cache: WeakHashMap<KClass<out RequestInterceptor>, RequestInterceptor?> by lazy { WeakHashMap() }

    override fun intercept(request: Request): Request =
            try {
                request.tag<Invocation>()?.method()?.annotation<RequestIntercepted>()?.value?.fold(request) { req, klass ->
                    try {
                        (interceptors[klass] ?: cache.getsOrPut(klass) {
                            klass.java.constructors.first()?.newInstance() as RequestInterceptor?
                        })?.intercept(req)
                    } catch (e: Throwable) { null } ?: req
                }
            } catch (e: Throwable) { null } ?: request
}